They should return the suit to it's grey color, and make it more simple in nature.

They should also focus on the detective aspect of batman in this series rather than his fighting skills.

They should include the Tim drake version of robin to supplement the detective story line, and give him a decent origin story.

The villains should be a mix of batman villains, but also have justice league tie ins. I'd love to see lex luthor in a minor role, as well as Harley Quinn as setup for the new joker. Main villain could be someone who can tie Quinn and Luthor together. Like the Preston Payne version of clayface, whose star labs could be funded in part by lex luthor, but also tie in with Quinn when his mental health begins to slip.

They should dial down the playboy aspect of Bruce Wayne and make him more of a businessman, having Wayne enterprises connected to scientific research.

Batman should have plenty of toys, but not over the top stuff. A sleeker bat mobile that is more fun than function.